Hello, On Thu, 28 Apr 2016 09:33:32 -0500, Bjorn Helgaas wrote: > [+cc linux-pci, manually inserted reply, sorry again] > > Liviu wrote: > > On Wed, Apr 27, 2016 at 05:58:27PM -0500, Bjorn Helgaas wrote: > >> Looking at __arm_ioremap_pfn_caller() makes me > >> suspect that pci_remap_iospace() is not safe on arm. > > > Hmm, not sure how you reached that conclusion. __arm_ioremap_pfn_caller() > > does call in the end ioremap_page_range() for ARMv7 || ARM_LPAE, which is > > what pci_remap_iospace() does as well. Beside the possibly different > > pgprot_t values, what would make it unsafe for arm? > > The different pgprot_t is exactly what I'm worried about. The callers of > pci_ioremap_io() probably get the right thing (a pgprot tweaked to deal > with this Cortex problem), but other callers of ioremap_page_range(), > pci_remap_iospace() in particular, don't get that tweak: > > pci_ioremap_io > ioremap_page_range(..., __pgprot(get_mem_type(pci_ioremap_mem_type)->prot_pte)) > > pci_remap_iospace > ioremap_page_range(..., pgprot_device(PAGE_KERNEL)) > ioremap_pud_range(..., pgprot_device(PAGE_KERNEL)) > ioremap_pmd_range(..., pgprot_device(PAGE_KERNEL)) > ioremap_pte_range(..., pgprot_device(PAGE_KERNEL)) > set_pte_at(..., pfn_pte(pfn, pgprot_device(PAGE_KERNEL))) Indeed. Which is why we should get rid of one of the two interfaces. Since pci_remap_iospace() is the generic one, I guess that's the one we should migrate to. Thomas -- Thomas Petazzoni, CTO, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
